In conventional railcars, various layouts of pantographs for collecting electric power through overhead contact lines and respective high voltage devices, such as vacuum circuit breakers (VCB) and arresters (lightning arresters), have been proposed. For example, in a railcar disclosed in PTL 1, the pantograph is arranged on a roof of a car, and some high voltage devices, such as the vacuum circuit breaker and the arrester, are mounted under a floor of the car together with a main transformer, a main converter, a main electric motor, and the like. In the railcar of PTL 1, the electric power collected by the pantograph is supplied to the respective high voltage devices through electric power cables extending from on the roof to under the floor. Especially, such a layout is often adopted in railcars that travel at comparatively high speed (hereinafter may be simply referred to as “high speed railcars”). In the case of some express trains in countries other than Japan, the vacuum circuit breaker, the arrester, outdoor terminations, and the like are mounted on the roof.
In the high speed railcar in which a plurality of cars are coupled to one another, the pantograph arranged on the roof tends to become a noise source when the railcar travels at high speed. Therefore, the number of pantographs is set to be smaller than the number of cars coupled to one another. On this account, a branch joint for branching and connecting of a plurality of electric power cables is arranged on the roof of the car, and a part of the electric power cables connected to the branch joint are arranged to extend toward the other cars. Thus, the electric power collected by the pantograph is distributed to the other cars.